Digital BW, The Print

I'm refilling my 1280 carts with UT ink.  I have two sets of carts 
but am not sure if I should keep refilling the same cart until the 
foam prevents another filling or rotate between the two sets.  If I 
rotate should I seal up the top and bottom of the filled cart with 
tape to keep it from drying out until I'm ready to use it?  If I use 
the same cart how long can I keep the carts out of the printer before 
the chamber and nozzles dry out?  How do you folks handle this?

Thanks, again, for your help.

Tom